EXPERIMENT STATION EEPORT. 663 



Avitli (listiiu't offsets iimucdiately before the eyes, iipiai which rest 

 the aiiteainn". Six sing-le hairs on the anterior half of tlie head 

 arise from minnte pits ; two of these are sitnated further in front 

 than the others and occnpy the central portion. The eyes are black 

 and I'oniKh'd. The anteiinfe (Figure 8, 3) are exceeding-ly long and 

 slender, swollen at the base, followed by a wrinkled portion, im- 

 mediately above which arises a single long seta from a distinct 

 tnlu'i'f'le; a short distance from the apex is a slight offset which 

 sends forth two moderately long hairs, and the apex of the shaft is 

 terminated by a snmll peg and long, sharp spine. The mentnm 

 (Figure 8, 4) is broadly pentagonal in form, with one large central 

 tooth and three smaller ones on each side, becoming successively 

 larger toward the base; the attached hypopharynx is threedobed; 

 the central lobe set v.'ith short, stout pegs. The mandible is very 

 singular, departing in some respects from that of all known spe- 

 cies, and is best described by a reference to Figiiro 8, 5. It is a 

 chnid^y affair, possessing the usual fan-like structure and thr^e 

 long and a short, stout spine on the dorsal aspect. The peculiar 

 structure lies in the fleshy portion, which extends beyond the apex 

 of the teeth, thus indicating some special mode of feeding. The 

 thorax is broader than long, with deeply-cleft sides, forming large 

 teeth-like projections, from the apices of which arise two to four 

 long hairs; two pairs of shorter hairs are also on the anterior 

 margin, which extend forward over the head. The abdominal seg- 

 ments, 1 to 7, are subquadrate in form, the anterior ones produced 

 into sharp points at the sides, from the tips of each of which arise 

 two long liairs; the posterior segments are more transverse, with 

 one or two shorter hairs at the sides and with several additional 

 short hairs. Upon the dorsum of the eighth segment is situated the 

 anal siphon or air-tube (Figure 8, 6) ; this is broad at the basal 

 half, then suddenly constricted, and continues narrowly to apex, 

 there terminated by several recurved hooks. There is no double 

 row of s])ines or pecten, but on the ventral side are two very long 

 seta' from tubercles situated widely separate from each other. The 

 eighth segment also bears the lateral row of scales (Figure 8, 7), 

 five to eight in nund)er, with long spine-like apices, arranged in a 

 single regidar row. The ninth segment is longer than broad, with a 

 chitinized saddle on the dorsum extending one-fourth the width of 

 the scginent down the sides. Four very long double hairs consti- 

 tute the usual double dorsal tufts, and a ventral brush is absent. 



